[0]: https://heise.de/-4144515
[1]: https://www.intel.com/content/www/us/en/architecture-and-tec...
The first two just show, that the fix doesn't make performance worse when disabled.
"With non-virtualized operating systems."
"For non-virtualized environments or where it can be guaranteed that all virtualized guest operating systems are trusted." --> Aka disabled.
I've had the experience myself, and I can imagine that when a system is complex and hard to measure that you don't want an internet journalist running Cinebench to become the reference benchmark for your customers.
https://www.phoronix.com/scan.php?page=article&item=l1tf-for...
> Update: To note, no microcode changes/updates were made to the systems under test for this article, just testing/comparing the kernel patches.